1. Field of the Invention
The present invention relates to backpack carriers, and more particularily, to backpack carriers that have an helixical configuration that brings the center of gravity (COG) of the burden carried in closer approximation to the wearer's own COG and that have an attaching means for a variety of packs, and which permits carrying heavier than normal burdens much more comfortably with less energy expended by the wearer and with greater maneuverability.
2. Description of Prior Art
The problem that many people have with carrying a backpack is that a heavy load in the backpack tends to severly compress the shoulders of the user. This compressive force causes several adverse affects. Among these adverse affects are: restriction in the movement of the neck and the shoulders of the backpack wearer, intense pain in the shoulder muscle, and even severe restriction in the ability to breath. These problems exist even if an individual uses the most advanced backpacking equipment.
Simply put, there is still one major disadvantage with existing technologies; whether with of without shoulder straps, internal or external frames, or comprising devices for shifting much of the weight of the burden to the hips: the center of gravity of the burden lies far behind that of the COG of the wearer, which passes down through the vertebral body of the fourth lumbar and just anterior to the base of the sacrum. The more distant the COG of the burden is from the wearer's COG, the greater the Load Arm (distance) and thus the greater the Moments of Force (weight X distance=moments of force) generated. The greater the Moments of Force the greater the energy expended and discomfort to the wearer.
Backpacks that rest the burden on the shoulders by means of straps keep the COG of the burden closer to that of the wearer but restrict to some degree the movement of the neck, shoulders, ribs, and diaphram; more so as the weight increases. Those that shift the weight to the hips have done so at the expense of increasing the Load Arm of the burden from the wearer's COG. As the burden's COG moves posteriorly away from the wearer's COG, the same amount of weight will generate greater Moments of Force. These forces will then be vectored posteriorly and inferiorly creating a levering effect which will either apply more force to the shoulder straps, or if no shoulder straps and with a heavy enough burden, the waist belt will likely slip downward over the buttocks and fall to the ground.
The following U.S. Pat. Nos. 5,184,764, 4,676,418, 4,561,578, 4,479,595, 4,420,103, 4,303,186, and 4,013,201 demonstrate various improvements in backpack frames and carriers which utilize shoulder straps attached to rigid or flexible, internal or external frames. Some of these designs have afforded increased movement of the shoulders and/or hips, provided load-balancing mechanisms, tried to distribute some of the weight to the hips, and offered load-adjusting mechanisms to reduce fatigue. However much these devices may be an improvement over earlier models, they still allow a large portion of the weight to be borne by the shoulders. The present invention does not have weight-bearing shoulder straps and thus eliminates this problem.
With U.S. Pat. Nos. 5,160,073, 5,090,604, 4,369,903, 4,307,826, 4,189,076, 4,015,759, 3,923,216, and 3,516,596 attempts are made at shifting a larger portion of the weight to the hips and/or attempting to provide greater maneuverability. But here again whether they have rigid or flexible frames, with or without shoulder straps, the COG of the burden is not aligned with that of the wearer and in fact is sometimes made worse. Thus reducing the amount of burden that may comfortably be borne, increasing the energy expenditure, as well as reducing maneuverability.
What is needed is a mechanism that will vector the forces of gravity forward toward the sacral base, not backward toward the sacral apex. The present invention vectors the forces of the burden toward the sacral base to more closely align with the wearer's COG and thus substantially minimizing the possibility of the above related problems occuring.